Rotor Hub Maintenance System

ABSTRACT

A rotor hub maintenance system and method is disclosed. The system includes at least a rotor hub, a plurality of appendages that are operatively connectable to the hub, and a plurality of support members. The preferred embodiment provides that the support members simultaneously secure the hub and appendages a predetermined height above a reference surface and provide the only support for the hub and appendages.

RELATED APPLICATIONS

This application is a Divisional Application of U.S. Non-Provisionalapplication Ser. No. 12/367,385 filed Feb. 6, 2009, entitled “Rotor HubMaintenance System,” which claims domestic priority to U.S. ProvisionalApplication No. 61/065,084 filed Feb. 7, 2008, entitled “Rotor HubMaintenance System.”

FIELD OF THE INVENTION

The claimed invention relates to the field of maintenance equipment;more particularly, but not by way of limitation, to rotor hubmaintenance equipment.

BACKGROUND

The ability to safely and efficiently perform maintenance on rotor hubshas been a continual goal of the engineering service industry.

Historically, rotor hubs have been maintained through time consuming,potentially dangerous processes. For example, wind turbine rotors arecurrently removed and suspended during routine maintenance with severalcranes working in conjunction. Similarly, wind turbine rotors havetraditionally been removed and positioned for placement on a centralstand in close proximity to the ground. While cranes continue to suspendthe rotor hub assembly, workmen perform maintenance on the rotor hub.When finally placed on the central stand, the large scale of a typicalwind turbine in combination with a lack of support for protruding bladescreates potential hazards for workmen's continued maintenance of therotor hub. As the rotor is pivotally connected to the ground via a smallstand in the current maintenance process, any wind can create torquethat violently shifts the rotor hub assembly. Likewise, the currentmaintenance techniques require workmen to spend extended amounts of timeon their back under the suspended load. The slightest

With tedious maintenance being performed on wind turbines several timesa year, the dangers of maintenance worker safety is compounded by thestructural risks associated with current maintenance techniques. Thecurrent method of suspending a rotor hub with multiple cranes stressesthe joints, increases maintenance time, and decreases the useful life. Alack of support for individual rotor blades creates stresses throughoutthe rotor assembly as well as safety hazards for workmen under the rotorand operating suspension cranes. Further, a close proximity to theground does not provide workers with enough room to efficiently assessthe rotor hub and perform scheduled maintenance.

The combination of a large suspended load with inefficient area toperform maintenance generates a volatile situation that unnecessarilycreates hazards for workmen and the rotor hub assembly. Accordingly,there is a continuing need for improved systems for maintaining rotorhubs.

SUMMARY OF THE INVENTION

In accordance with the preferred embodiments, a rotor hub maintenancesystem includes at least a rotor hub, a plurality of appendages that areoperatively connectable to the hub, and a plurality of support members.The preferred embodiment provides that the support memberssimultaneously secure the hub and appendages a predetermined heightabove a reference surface and provide the only support for the hub andappendages.

In an alternative preferred embodiment, a method of maintaining a rotorhub includes at least the steps of providing a rotor hub, a plurality ofappendages that are operatively connectable to the hub, and a pluralityof support members. Further, the rotor hub and appendages aresimultaneously supported with only the support members.

These and various other features and advantages that characterize theclaimed invention will be apparent upon reading the following detaileddescription and upon review of the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 displays a top view of the preferred embodiment of the rotor hubmaintenance system;

FIG. 2 shows a top view of an alternative embodiment of the rotor hubmaintenance system;

FIG. 3 illustrates a front view of the appendage support membercomponent of the rotor hub maintenance system;

FIG. 4 displays a side view of the appendage support member component ofFIG. 3 in accordance with various embodiments of the present invention;

FIG. 5 shows a side view of the hub support member component of therotor hub maintenance system;

FIG. 6 provides a top view of the hub support member component of FIG.5;

FIG. 7 illustrates an exploded front perspective view of the rotor hubmaintenance system in a preferred embodiment;

FIG. 8 displays an exploded front perspective view of the rotor hubmaintenance system in an alternative embodiment;

FIG. 9 shows an exploded front perspective view of the rotor hubmaintenance system in an alternative embodiment;

FIG. 10 provides a flow chart representation of a rotor hub maintenanceoperation performed in accordance with various embodiments of thepresent invention.

DETAILED DESCRIPTION

Reference will now be made in detail to one or more examples of theinvention depicted in the figures. Each example is provided by way ofexplanation of the invention, and not meant as a limitation of theinvention. For example, features illustrated or described as part of oneembodiment may be used with another embodiment to yield still adifferent embodiment. Other modifications and variations to thedescribed embodiments are also contemplated within the scope and spiritof the invention.

Referring to the drawings, FIG. 1 shows a top view of the preferredembodiment of the rotor hub maintenance system 100. The rotor hubmaintenance system 100 is characterized by a rotor hub 102 to which aplurality of appendages 104 are operatively connectable. Severalappendage support members 106 interact with the appendages 104 tosupport the rotor hub 102. In an alternative embodiment, a hub supportmember 108 is disposed at the vertex of the appendages 104 whileinteracting with the rotor hub 102.

It should be noted that the number of appendages 104 shown in FIG. 1 isnot limiting and any number of appendages can be radially disposedaround the hub while keeping with the spirit of this invention.Similarly, the shape of the appendages can be any profile withouthindering the various embodiments of the present invention. Also, theappendage support members and the hub support member are referred to as“support members” for simplicity. However, the use of the hub supportmember 108 as part of the hub maintenance system 100 is not required andcan be omitted if necessary.

As discussed below, the rotor hub maintenance system 100 allows for therotor hub 102 and appendages 104 to be secured by the support members apredetermined distance above a reference plane. FIG. 1 displays the topview of how the hub and appendages are secured by the support members ina preferred embodiment. It should be noted that the hub 102 andappendages 104 are balanced and upheld by the support members that arepreferably capable of supporting the entire weight of each component.That is, each support member securing each appendage is capable ofsupporting the entire weight of the appendage. Likewise, the hub supportmember is capable of securing and supporting at least the weight of therotor hub 102.

FIG. 2 shows a top view of an alternative embodiment of the rotor hubmaintenance system. The alternative embodiment illustrates multipleappendage support members interacting with each appendage 104. Further,each appendage 104 is disconnected with the rotor hub 102 whichincreases access to vital areas of the rotor hub and appendages formaintenance. The support of the rotor hub 102 is fully facilitated bythe hub support member in this alternative embodiment. As FIG. 2displays, each appendage 104 as well as the rotor hub 102 are autonomousfrom each other component and can be replaced or repaired individuallyor in combination as needed.

The use of multiple appendage support members 106 for each appendage 104provides the ability to fully balance and control the appendage 104.This greatly improves efficiency of variable pitch appendages that havea skewed leading edge. In addition, proper maintenance of the appendages104 and rotor hub 102 often mandates the inspection of small areas thatare not easily accessible when the appendages 104 are connected to therotor hub 102.

In FIG. 3, a front view of the appendage support member 106 is shownconstructed in accordance with various embodiments of the presentinvention. The appendage support member 106 contains a main body portion202. In a preferred embodiment, the main body portion 202 includes afirst density portion 204, a second density portion 206, and a thirddensity portion 208. In an alternative embodiment, the main body portion202 includes a material of constant density. However, it should be notedthat the main body portion 202 can comprise any number of layers ofvarious densities.

Likewise, the various density portions can be composed of any variety ofenergy absorbing material including, but not limited to, foam, plastic,or metal. For example, the first density portion 204 can be constructedof a honeycomb metal while the layers of the second density portions 206are made of varying density foam. However, the density portions shown inFIGS. 3 and 4 do not restrict the use of multiple materials being packedinto the main body portion 202. That is, any, or all, of the densityportions of the main body portion 202 can be constructed of an outercontainment shell filled with energy absorbing pieces of material.

Further, the main body portion 202 is supported by an adjustment member210 that provides a base for the main body portion 202 and includes amovement member 212 which supports an axle 214 and a wheel 216. Apreferred embodiment has the wheel 216 being disengaged from a referencesurface when not in use. That is, the wheel 216 is not touching theground while in place. To move the appendage support member 106, a userwould tilt the support member 106 to engage the wheel 216 to the groundand enable movement.

FIG. 4 shows a side view of the appendage support member 106. Apreferred embodiment of the appendage support member 106 includes themain body portion 202 configured in a sloped shape that is defined bythe first density portion 204 having a smaller surface area than thethird density portion 208. However, the shape, surface area, andorientation of the various density portions shown in FIGS. 3 and 4 arenot limiting and can be a number of various embodiments that providenecessary support for an appendage.

In an alternative embodiment, the adjustment member 210 can be removedfrom the appendage support member 106. Hence, the adjustment member 210can be permanently or temporarily coupled to the appendage supportmember 106 to enable movement.

In FIG. 5, a side view of a hub support member 108 is illustrated asconstructed in accordance with various embodiments of the presentinvention. The hub support member 108 preferably includes a main bodymember 302 to which a stud retention member 304 is operativelyconnected. In a preferred embodiment, an adjustment member 306 providesa base for the main body member 302. Similarly to the adjustment member210 of FIGS. 3 and 4, the adjustment member 306 includes a movementmember 308, an axle 310, and at least one wheel 312 to enable efficientmovement of the hub support member 306.

As with the adjustment member 210 of FIGS. 3 and 4, the adjustmentmember 306 allows the wheel to be disengaged from a reference surfacewhile the hub support member 108 is set. It should be noted that the hubsupport member 108 can be removed from the adjustment member 306, asneeded.

FIG. 6 displays a top view of the hub support member 108 of FIG. 5. Thehub support member 108 includes a main body member 302 to which a studretention member 304 is operatively connected. In various embodiments,the stud retention member 304 can include a plurality of stud members314 to operatively secure the studs of a rotor hub 102. In analternative preferred embodiment, the adjustment member 306 interactingwith the main body member 302 includes a plurality of wheels 312

In addition, the number and orientation of the stud members 314 shown inFIG. 6 are not limited and can be placed in any configuration thatallows for attachment of a rotor hub. It is contemplated that the studmembers 314 provide a plurality of fastening apertures 316 toaccommodate the various possible fasteners of the rotor hub. Forexample, the stud members 314 can have bolt holes to which the rotor hubbolts are received and fastened. As a result, the rotor hub iseffectively mounted to the hub support member 108 and can be examinedand repaired without fear of instability.

In FIG. 7, an exploded perspective view of the rotor maintenance system100 is shown. The rotor hub maintenance system 100 preferably includes arotor hub 102 operatively connectable to a plurality of appendages 104.The rotor hub 102 also preferably includes a stud region 110 whichoperatively secures to the stud retention member 304 of the hub supportmember 108. Further, the appendages 104 are each being shown supportedby blade support members 106. The preferred embodiment includes theappendage support members 106 interacting with the appendages 104 tosupport the rotor hub 102 a predetermined height off of a referencesurface 112.

One skilled in the art can recognize that in operation the appendagesupport members 106 engage the appendages 104 on multiple sides toprovide balance and control. Similarly, the stud retention member 304 iscapable of receiving and securing one, or many, of the studs in the studregion 110. It should be noted that the adjustment members for thesupport members are present during operation shown in FIG. 7, but arenot required. Also, the hub support member 108 can be optionally omittedfrom the system 100 when the appendages 104 and rotor hub 102 areconnected.

FIG. 8 illustrates an exploded perspective view of the rotor hubmaintenance system in an alternative embodiment. The alternativeembodiment includes multiple appendages support members 106 interactingwith each appendage 104. The plurality of support members 106 and 108support the rotor hub 102 and appendages 104 a predetermined height offof a reference surface 112. A hoisting mechanism 320 is shown providingadditional support for the hub 102 and appendages 104. In someembodiments, the hoisting mechanism 320 comprises a number of hoistingstraps 322 connected to the appendages 104 and a hoisting member 324that is attached to a hoisting apparatus 326.

The hoisting mechanism 320 displayed in FIG. 8 is merely arepresentation of a possible additional support. In an alternativepreferred embodiment, the hoisting mechanism is a crane that is utilizedto position the appendages 104 and rotor hub 102 onto the supportmembers. Further in a preferred embodiment, the hoisting mechanism 320is disconnected from the appendages 104 and rotor hub 102 afterpositioning so that the support members secure and balance the entireweight of the appendages 104 and rotor hub 102.

Attention should be drawn to the appendage support members 106 whichhave been removed from their respective adjustment members so that thethird density portion engages the reference surface 112. Likewise, theheights of the appendage support members 106 closest to the rotor hub102 are taller than the distal appendage support members 106. Meanwhile,the hub support member 108 remains coupled to an adjustment member. Assuch, the support members can support the rotor hub and appendages invarious configurations that may include different heights, presence ofadjustment members, and positioning mechanisms.

While a crane is shown in FIG. 8 as an embodiment of the hoistingmechanism 320, the representation is not limiting and the mechanism canbe anything that is capable of supporting and positioning the appendages104 and rotor hub 102 onto the support members.

In FIG. 9, an exploded perspective view of the rotor hub maintenancesystem in an alternative embodiment is shown. The appendages 104 areeach shown detached from the rotor hub 102 and interacting with multipleappendage support members 106. This alternative embodiment includes therotor hub 102 interacting with the hub support member 108 to restrainthe rotor hub 102 a predetermined height off of a reference surface 112.The stud region 110 of the rotor hub 102 is also displayed operativelysecured to the stud retention member 304 of the hub support member 108.

It should be noted that the position of the appendage support members106 in relation to the appendages 104 are different in FIG. 9 thandisplayed in FIG. 8. This illustrates the non-limiting orientation ofthe appendage support members 106 and one of the many possibleconfigurations that are capable of securing the full weight of eachappendage while disconnected from the rotor hub 102.

FIG. 10 provides a flow chart of a rotor hub maintenance operation 330performed in accordance with various embodiments of the presentinvention. The operation 330 begins with a rotor hub, plurality ofappendages, and plurality of support members as a lift member-safetylatch combination being provided at step 332. A hoisting mechanism isused in step 334 to position the appendages and rotor hub in closeproximity to the support members. In step 336, the support members arepositioned at predetermined locations on the appendages and rotor hub toenable secure support after the hoisting mechanism is disconnected.

Further in step 338, the stud region of the rotor hub is fastened to thehub support member while the appendages rest in the recessed portion ofeach appendage support member. Step 340 involves disconnecting thehoisting straps for the appendages so that the support members providethe only support. An inspection, repair, or replacement of anycomponents of the rotor hub or appendages is conducted in step 342before the hoisting straps are reattached in step 344. Finally in step346, the rotor hub and appendages are returned to an original location.

The various steps associated with the maintenance operation 330 aremerely representations of a possible procedure. Thus, various steps canbe omitted or substituted with other steps while adhering to the spiritof this invention.

While the invention has been described in connection with a preferredembodiment, it is not intended to limit the scope of the invention tothe particular form set forth, but on the contrary, it is intended tocover such alternatives, modifications, and equivalents as may beincluded within the spirit and scope of the invention as defined by theappended claims. Furthermore, in various embodiments the rotor hub andappendages can combine to comprise a wind turbine capable of generatingelectrical energy from the wind. That is, the rotor hub and appendagescan be wind turbine components that connect and function as a windturbine.

It will be clear that the present invention is well adapted to attainthe ends and advantages mentioned as well as those inherent therein.While presently preferred embodiments have been described for purposesof this disclosure, numerous changes may be made which will readilysuggest themselves to those skilled in the art and which are encompassedby the appended claims.

1. A rotor hub maintenance system comprising: a rotor hub; a pluralityof appendages operatively connectable to said hub; and a. plurality ofsupport members that simultaneously secure the hub and appendages apredetermined height off of a reference surface, wherein the supportmembers provide the only support for the hub and appendages, and whereineach of the plurality of appendage support members comprising: a mainbody; an axle connected to said main body; and a wheel operativelyconnected to said axle.
 2. The rotor hub maintenance system of claim 1,in which the rotor hub and appendages combine to form a wind turbine. 3.The rotor hub maintenance system of claim 1, in which the plurality ofsupport members include a hub support member and a number of appendagesupport members,
 4. The rotor hub maintenance system of claim 1, inwhich the rotor hub and appendages are positioned onto the supportmembers by a hoisting mechanism,
 5. The rotor hub maintenance system ofclaim 1, in which the wheel is disengaged from the reference plane afterpositioning the support members.
 6. The rotor hub maintenance system ofclaim 3, in which the appendage support members comprise a recessedportion that supports each appendage on multiple sides,
 7. The rotor hubmaintenance system of claim 3, in which the appendage support memberscomprise multiple layers of energy absorbing material.
 8. The rotor hubmaintenance system of claim 3, in which the hub support memberoperatively engages the rotor hub and is positioned at a vertex of theappendages.
 9. The rotor hub maintenance system of claim 3, in which thehub support member secures the rotor hub with fastening bolts.
 10. Therotor hub maintenance system of claim 3, in which the appendage supportmembers are each capable of supporting the weight of each appendage. 11.The rotor hub maintenance system of claim 3, in which a single hubsupport member interacts with the rotor hub while each appendageinteracts with multiple appendage support members.